#
# Take a file of format
# movie:
# user,rating,date
# user,rating,date
# ...
# movie:
# user,rating,date
# ...
#
# and produce an equivalent file of format
# user:
# movie,rating,date
# ...
# user:
# movie,rating,date
#
# NOTE: if sort dies because of lack of temporary space, try setting the TMPDIR
# env var to another physical drive.
#
# The resulting file is sorted ascending by user id (numerically, not
# lexically), and the movies are sorted ascending by movie id (numerically)
# within each block.
#
# You can also use it in the inverse way (interchanging users and movies), and
# the date is optional.
#

perl src/block_to_tuple.pl | \
  sort -t ',' -k 2n,2 -k 1n,1 | \
  awk -F',' '{printf("%d,%d",$2,$1)};{for (i=3; i<=NF; i++)
  printf(",%s",$i)};{printf("\n")};' | \
  perl src/tuple_to_block.pl

# Copyright (c) 2009 John Lees-Miller
# 
# Permission is hereby granted, free of charge, to any person
# obtaining a copy of this software and associated documentation
# files (the "Software"), to deal in the Software without
# restriction, including without limitation the rights to use,
# copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following
# conditions:
# 
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
# OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
# HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
# OTHER DEALINGS IN THE SOFTWARE.

